Fort Willoughby, Charlotte Amalie, St. Thomas, VI

Significance: Fort Willoughby is significant as both a Danish and British military defensive work on Hassel Island. Originally called Prince Frederik's Battery, it was built by the government of the Danish West Indies in 1777-1780 on the southeastern end of the peninsula known at that time as Estate Orkanhullet (Hurricane Hole), now Hassel Island. Located on the western border of St. Thomas Harbor, the cannons of Fort Willoughby defended the harbor entrance from colonial rivals and prevented privateers from seizing merchant ships in the harbor. On March 3, 1801, Fort Willoughby participated in a skirmish with Danish brig of war HDMS Lougen in driving off a British sloop of war, HMS Arab. British troops later used the battery and renamed it Fort Willoughby during their first occupation of St. Thomas in 1801, and it was again repaired and used during the second British occupation from 1807-1815. Fort Willoughby was listed in the National Register of Historic Places in 1976 for its architectural, commercial, and military significance.
Unprocessed Field note material exists for this structure: N2101
Survey number: HABS VI-90
Building/structure dates: 1777-1780 Initial Construction
Building/structure dates: 1801 Subsequent Work
Building/structure dates: after 1807 Subsequent Work
Building/structure dates: after 1948 Subsequent Work
Building/structure dates: after 2010 Subsequent Work
National Register of Historic Places NRIS Number: 76001862